By Lilly Tozer How the brain processes visual information — and its perception of time — is heavily influenced by what we’re looking at, a study has found. In the experiment, participants perceived the amount of time they had spent looking at an image differently depending on how large, cluttered or memorable the contents of the picture were. They were also more likely to remember images that they thought they had viewed for longer. The findings, published on 22 April in Nature Human Behaviour1, could offer fresh insights into how people experience and keep track of time. “For over 50 years, we’ve known that objectively longer-presented things on a screen are better remembered,” says study co-author Martin Wiener, a cognitive neuroscientist at George Mason University in Fairfax, Virginia. “This is showing for the first time, a subjectively experienced longer interval is also better remembered.” Research has shown that humans’ perception of time is intrinsically linked to our senses. “Because we do not have a sensory organ dedicated to encoding time, all sensory organs are in fact conveying temporal information” says Virginie van Wassenhove, a cognitive neuroscientist at the University of Paris–Saclay in Essonne, France. Previous studies found that basic features of an image, such as its colours and contrast, can alter people’s perceptions of time spent viewing the image. In the latest study, researchers set out to investigate whether higher-level semantic features, such as memorability, can have the same effect. © 2024 Springer Nature Limited

Keyword: Attention; Vision
Link ID: 29269 - Posted: 04.24.2024

By Bill Wasik and Monica Murphy What makes a desert tortoise happy? Before you answer, we should be more specific: We’re talking about a Sonoran desert tortoise, one of a few species of drab, stocky tortoises native to North America’s most arid landscapes. Adapted to the rocky crevices that striate the hills from western Arizona to northern Mexico, this long-lived reptile impassively plods its range, browsing wildflowers, scrub grasses and cactus paddles during the hours when it’s not sheltering from the brutal heat or bitter cold. Sonoran desert tortoises evolved to thrive in an environment so different from what humans find comfortable that we can rarely hope to encounter one during our necessarily short forays — under brimmed hats and layers of sunblock, carrying liters of water and guided by GPS — into their native habitat. This past November, in a large, carpeted banquet room on the University of Wisconsin’s River Falls campus, hundreds of undergraduate, graduate and veterinary students silently considered the lived experience of a Sonoran desert tortoise. Perhaps nine in 10 of the participants were women, reflecting the current demographics of students drawn to veterinary medicine and other animal-related fields. From 23 universities in the United States and Canada, and one in the Netherlands, they had traveled here to compete in an unusual test of empathy with a wide range of creatures: the Animal Welfare Assessment Contest. That morning in the banquet room, the academics and experts who organize the contest (under the sponsorship of the American Veterinary Medical Association, the nation’s primary professional society for vets) laid out three different fictional scenarios, each one involving a binary choice: Which animals are better off? One scenario involved groups of laying hens in two different facilities, a family farm versus a more corporate affair. Another involved bison being raised for meat, some in a smaller, more managed operation and others ranging more widely with less hands-on human contact. © 2024 The New York Times Company

Keyword: Animal Rights; Emotions
Link ID: 29268 - Posted: 04.24.2024

By Angie Voyles Askham The ability of amphibians to metamorphosize and, in some cases, regenerate limbs and even brain tissue raises puzzling yet fundamental questions about how a nervous system wires itself up. For example, if a frog’s legs don’t exist when its brain begins to develop—those limbs later replace its tadpole tail—how are the neural connections maintained such that, once the legs take shape, a frog can move them? “How many connections are there between the spinal cord and the brain? How do they change over metamorphosis?” asks Lora Sweeney, assistant professor at the Institute of Science and Technology Austria. To find out, Sweeney and her colleagues decided to screen a panel of adeno-associated viruses (AAVs) in two species of frog and a newt. These viruses are commonly used to genetically manipulate brain cells in rodents and monkeys, but they have not been proven useful in amphibian experiments. With the right techniques, most common AAVs can deliver genes to amphibian cells through a process called transduction, according to Sweeney’s unpublished results, though the most effective viruses vary by species. These amphibian-friendly AAVs can be used to trace neuronal connections and track groups of neurons born at the same time, the new work shows. And a subset of these same AAVs can also transduce cells in axolotls, newts’ fuzzy-gilled Mexican cousins, according to another preprint from an independent team. Both preprints were posted on bioRxiv in February. “It’s a big game-changer,” says Helen Willsey, assistant professor of psychiatry at the University of California, San Francisco, who was not involved in either study but works with amphibian models. “It opens up a lot of doors for new experiments.” Other researchers had previously tried to get AAVs to transduce cells in frogs and fish, with little success. © 2024 Simons Foundation

Keyword: Brain imaging; Evolution
Link ID: 29267 - Posted: 04.24.2024

By John Horgan Philosopher Daniel Dennett died a few days ago, on April 19. When he argued that we overrate consciousness, he demonstrated, paradoxically, how conscious he was, and he made his audience more conscious. Dennett’s death feels like the end of an era, the era of ultramaterialist, ultra-Darwinian, swaggering, know-it-all scientism. Who’s left, Richard Dawkins? Dennett wasn’t as smart as he thought he was, I liked to say, because no one is. He lacked the self-doubt gene, but he forced me to doubt myself. He made me rethink what I think, and what more can you ask of a philosopher? I first encountered Dennett’s in-your-face brilliance in 1981 when I read The Mind’s I, a collection of essays he co-edited. And his name popped up at a consciousness shindig I attended earlier this month. To honor Dennett, I’m posting a revision of my 2017 critique of his claim that consciousness is an “illusion.” I’m also coining a phrase, “the Dennett paradox,”which is explained below. Of all the odd notions to emerge from debates over consciousness, the oddest is that it doesn’t exist, at least not in the way we think it does. It is an illusion, like “Santa Claus” or “American democracy.” René Descartes said consciousness is the one undeniable fact of our existence, and I find it hard to disagree. I’m conscious right now, as I type this sentence, and you are presumably conscious as you read it (although I can’t be absolutely sure). The idea that consciousness isn’t real has always struck me as absurd, but smart people espouse it. One of the smartest is philosopher Daniel Dennett, who has been questioning consciousness for decades, notably in his 1991 bestseller Consciousness Explained. © 2024 SCIENTIFIC AMERICAN,

Keyword: Consciousness
Link ID: 29266 - Posted: 04.24.2024

By Diana Kwon Overall, people in U.S. live longer than they did a hundred years ago. The growing number of people reaching old age has meant an increased proportion are at risk of developing dementia or Alzheimer’s disease, illnesses that typically strike later in life. However, researchers have found that, in the U.S. and elsewhere, dementia risk may actually be decreasing, at least in a subset of the population. A new study provides a potential explanation for this trend: Human brains may be getting larger—and thus more resilient to degeneration—over time. Several large population studies in countries including the U.S. and Great Britain have found that, in recent decades, the number of new cases, or incidence, of dementia has declined. Among these is the Framingham Heart Study, which has been collecting data from individuals living in Framingham, Massachusetts since 1948. Now accommodating a third generation of participants, the study includes data from more than 15,000 people. In 2016, Sudha Seshadri, a neurologist at UT Health San Antonio and her colleagues published findings revealing that while the prevalence—the total number of people with dementia—had increased, the incidence had declined since the late 1970s. “That was a piece of hopeful news,” Seshadri says. “It suggested that over 30 years, the average age at which somebody became symptomatic had gone up.” These findings left the team wondering: What was the cause of this reduced dementia risk? While the cardiovascular health of the Framingham residents and their descendants—which can influence the chances of developing dementia—had also improved over the decades, this alone could not fully explain the decline. On top of that, the effect only appeared in people who had obtained a high school diploma, which, according to Seshadri, pointed to the possibility that greater resilience against dementia may result from changes that occur in early life. © 2024 SCIENTIFIC AMERICAN,

Keyword: Development of the Brain; Learning & Memory
Link ID: 29265 - Posted: 04.20.2024

By Dan Falk In 2022, researchers at the Bee Sensory and Behavioral Ecology Lab at Queen Mary University of London observed bumblebees doing something remarkable: The diminutive, fuzzy creatures were engaging in activity that could only be described as play. Given small wooden balls, the bees pushed them around and rotated them. The behavior had no obvious connection to mating or survival, nor was it rewarded by the scientists. It was, apparently, just for fun. The study on playful bees is part of a body of research that a group of prominent scholars of animal minds cited today, buttressing a new declaration that extends scientific support for consciousness to a wider suite of animals than has been formally acknowledged before. For decades, there’s been a broad agreement among scientists that animals similar to us — the great apes, for example — have conscious experience, even if their consciousness differs from our own. In recent years, however, researchers have begun to acknowledge that consciousness may also be widespread among animals that are very different from us, including invertebrates with completely different and far simpler nervous systems. The new declaration, signed by biologists and philosophers, formally embraces that view. It reads, in part: “The empirical evidence indicates at least a realistic possibility of conscious experience in all vertebrates (including all reptiles, amphibians and fishes) and many invertebrates (including, at minimum, cephalopod mollusks, decapod crustaceans and insects).” Inspired by recent research findings that describe complex cognitive behaviors in these and other animals, the document represents a new consensus and suggests that researchers may have overestimated the degree of neural complexity required for consciousness. © 2024the Simons Foundation.

Keyword: Consciousness; Evolution
Link ID: 29264 - Posted: 04.20.2024

By Gillian Dohrn No one wants to eat when they have an upset stomach. To pinpoint exactly where in the brain this distaste for eating originates, scientists studied nauseated mice. The work, published in Cell Reports on 27 March1, describes a previously uncharacterized cluster of brain cells that fire when a mouse is made to feel nauseous, but don’t fire when the mouse is simply full. This suggests that responses to satiety and nausea are governed by separate brain circuits. “With artificial activation of this neuron, the mouse just doesn’t eat, even if it is super hungry,” says Wenyu Ding at the Max Planck Institute for Biological Intelligence in Martinsried, Germany, who led the study. Ding and colleagues suspected that this group of neurons was involved in processing negative experiences, such as feeling queasy, so they injected the mice with a chemical that induces nausea and then scanned the animals’ brains. This confirmed that the neurons are active when mice feel nauseous. Using a light-based technique called optogenetics, the team artificially activated the neurons of mice that had been deprived of food in the hours before the experiment. When the neurons were ‘off’, the mice ate. When the researchers turned them on, the mice walked away mid-chow. These brain cells could influence how fast you eat — and when you stop Researchers also blocked the activity of these neurons in nauseated mice that were hungry and found that the mice overcame their nausea to eat. © 2024 Springer Nature Limited

Keyword: Obesity; Chemical Senses (Smell & Taste)
Link ID: 29263 - Posted: 04.20.2024

By Ingrid Wickelgren Ishmail Abdus-Saboor has been fascinated by the variety of the natural world since he was a boy growing up in Philadelphia. The nature walks he took under the tutelage of his third grade teacher, Mr. Moore, entranced him. “We got to interact and engage with wildlife and see animals in their native environment,” he recalled. Abdus-Saboor also brought a menagerie of creatures — cats, dogs, lizards, snakes and turtles — into his three-story home, and saved up his allowance to buy a magazine that taught him about turtles. When adults asked him what he wanted to be when he grew up, “I said I wanted to become a scientist,” he said. “I always raised eyebrows.” Abdus-Saboor did not stray from that goal. Today, he is an associate professor of biological sciences at the Mortimer B. Zuckerman Mind Brain Behavior Institute at Columbia University, where he studies how the brain determines whether a touch to the skin is painful or pleasurable. “Although this question is fundamental to the human experience, it remains puzzling to explain with satisfying molecular detail,” he said. Because the skin is our largest sensory organ and a major conduit to our environment, it may hold clues for treating conditions from chronic pain to depression. To find those clues, Abdus-Saboor probes the nervous system at every juncture along the skin-to-brain axis. He does not focus on skin alone or home in on only the brain as many others do. “We merge these two worlds,” he said. That approach, he added, requires mastering two sets of techniques, reading two sets of literature and attending two sets of scientific meetings. “It gives us a unique leg up,” he said. It has led to a landmark paper published last year in Cell that laid out the entire neural circuit for pleasurable touch. © 2024 Simons Foundation.

Keyword: Pain & Touch; Emotions
Link ID: 29262 - Posted: 04.20.2024

By Saima S. Iqbal Before becoming a researcher, Aimee Grant worked as a caregiver for six years in Cornwall, England, supporting autistic adults in group homes. But only more than a decade later, after befriending an autistic colleague at a sociology conference, did she realize she was autistic herself. The stereotypical view of autism as a brain impairment more commonly found in men made it difficult for Grant to make sense of her internal world. From an early age, she struggled to pick up on important social cues and found the sounds and scents in her environment distractingly painful. But like many children in her generation, she says, she grew accustomed to either dismissing or disguising her discomfort. It was by listening to some of the stories of her female peers that Grant saw that the label could fit. Receiving a diagnosis in 2019 prompted her to “reframe [my] entire life,” she says. She began working with her mind rather than against it. She no longer felt the same pressure to seem as nonautistic as possible with friends and family members, and she began to make use of accommodations at work, such as a light filter for her computer monitor. Today, as a public health researcher at Swansea University in Wales, Grant aims to uncover the lived experience of autistic people. Many scientists and clinicians see autism as a developmental disorder that hinders a person’s ability to understand and communicate with others. Grant believes that their work often obscures the heterogeneity of autism. And because many studies view autism as a disease, they overlook the reality that autistic people can feel more disabled by widespread misunderstanding and a lack of accommodations than by autistic traits themselves. © Society for Science & the Public 2000–2024.

Keyword: Autism
Link ID: 29261 - Posted: 04.20.2024

By McKenzie Prillaman Wegovy, Ozempic and similar weight-loss drugs have become some of the most popular medications in the world. But legions of people are also quitting them. About two-thirds of those in the United States who started taking a drug of this class, known as GLP-1 agonists, in 2021 had stopped using them within a year, according to an industry analysis. Researchers and clinicians often view GLP-1 agonists as lifelong treatments. But myriad factors can force individuals off the medications. People might lose the means to pay for the costly drugs, experience brutal side effects, be affected by continuing shortages or be offered limited-term prescriptions. The UK National Health Service (NHS), for instance, provides only two years of coverage for people taking the drugs for weight loss. As the number of people with obesity continues to rise — the World Health Organization estimates that more than one billion people, or one-eighth of the global population, now have obesity — researchers have been answering a few key questions about what happens when people stop taking these medications for weight management. What happens to weight and health when people quit? Ozempic and Wegovy are both brand names for the drug semaglutide, which has been prescribed for several years to treat type 2 diabetes (Ozempic) and, since 2021, to those who are overweight or have obesity (Wegovy). The treatment’s aim is to reduce the risk of health complications posed by a large amount of excess body fat, such as heart and liver disease and certain cancers. The drug curbs hunger and food intake by mimicking a hormone, released by the gut after eating, that affects brain regions involved in appetite and reward. Research has shown what happens when people stop taking GLP-1 agonists. Many regain a substantial amount of what they lost with the help of the medications. The body naturally tries to stay around its own weight point, a pull that obesity specialist Arya Sharma likens to a taut rubber band. © 2024 Springer Nature Limited

Keyword: Obesity
Link ID: 29260 - Posted: 04.16.2024

Allison Aubrey Imagine if every moment is filled with a high-pitched buzz or ring that you can't turn off. More than 25 million adults in the U.S., have a condition called tinnitus, according to the American Tinnitus Association. It can be stressful, even panic-inducing and difficult to manage. Dozens of factors can contribute to the onset of tinnitus, including hearing loss, exposure to loud noise or a viral illness. There's no cure, but there are a range of strategies to reduce the symptoms and make it less bothersome, including hearing aids, mindfulness therapy, and one newer option – a device approved by the FDA to treat tinnitus using electrical stimulation of the tongue. The device has helped Victoria Banks, a singer and songwriter in Nashville, Tenn., who developed tinnitus about three years ago. "The noise in my head felt like a bunch of cicadas," Banks says. "It was terrifying." The buzz made it difficult for her to sing and listen to music. "It can be absolutely debilitating," she says. Banks tried taking dietary supplements, but those didn't help. She also stepped up exercise, but that didn't bring relief either. Then she read about a device called Lenire, which was approved by the FDA in March 2023. It includes a plastic mouthpiece with stainless steel electrodes that electrically stimulate the tongue. It is the first device of its kind to be approved for tinnitus. "This had worked for other people, and I thought I'm willing to try anything at this point," Banks recalls. She sought out audiologist Brian Fligor, who treats severe cases of tinnitus in the Boston area. Fligor was impressed by the results of a clinical trial that found 84% of participants who tried Lenire experienced a significant reduction in symptoms. He became one of the first providers in the U.S. to use the device with his patients. Fligor also served on an advisory panel assembled by the company who developed it. © 2024 npr

Keyword: Hearing
Link ID: 29259 - Posted: 04.16.2024

By Helen Bradshaw With its hairless silicone skin and blue complexion, Emo the robot looks more like a mechanical re-creation of the Blue Man Group than a regular human. Until it smiles. In a study published March 27 in Science Robotics, researchers detail how they trained Emo to smile in sync with humans. Emo can predict a human smile 839 milliseconds before it happens and smile back. Right now, in most humanoid robots, there’s a noticeable delay before they can smile back at a person, often because the robots are imitating a person’s face in real time. “I think a lot of people actually interacting with a social robot for the first time are disappointed by how limited it is,” says Chaona Chen, a human-robot interaction researcher at the University of Glasgow in Scotland. “Improving robots’ expression in real time is important.” Through synced facial expressions, future iterations of robots could be sources of connection in our loneliness epidemic, says Yuhang Hu, a roboticist at Columbia University who, along with colleagues, created Emo (SN: 11/7/23). Cameras in the robot’s eyes let it detect subtleties in human expressions that it then emulates using 26 actuators underneath its soft, blue face. To train Emo, the researchers first put it in front of a camera for a few hours. Like looking in a mirror would do for humans and their muscles, looking at itself in the camera while researchers ran random motor commands on the actuators helped Emo learn the relationships between activating actuators in its face and the expressions it created. “Then the robot knows, OK, if I want to make a smiley face, I should actuate these ‘muscles,’” Hu says. © Society for Science & the Public 2000–2024.

Keyword: Emotions; Robotics
Link ID: 29258 - Posted: 04.16.2024

By Angie Voyles Askham Larry Young, a neuroscientist known for illuminating oxytocin’s outsized role in social bonding, died of a heart attack last month at the age of 57. In his 30-year career at Emory University, Young teased apart the neurobiology of love and relationships—from the receptors that make voles monogamous to the hormones that shape sociability in psychiatric disorders. He founded and directed both the Center for Translational Social Neuroscience and the Silvio O. Conte Center for Oxytocin and Social Cognition at Emory, and he helped establish the Laboratory of Social Neural Networks in Tsukuba, Japan. “His impact has been enormous,” says Steven Phelps, professor of integrative biology at the University of Texas at Austin, who was Young’s first postdoctoral researcher at Emory. “He brought molecular biology to what we would call non-model organisms, the species that are normally neglected by mainstream science.” Young also fostered collaborations through the many international conferences he organized, and he raised the public profile of neuroscience research through his dedication to science communication. He served as a hub within the field of social neuroscience—someone who connected others across continents and research modalities—says Steve Chang, associate professor of psychology and neuroscience at Yale University. “Everyone feels there is now a giant hole.” Young grew up on a farm in Sylvester, Georgia, a small town that claims the title of “Peanut Capital of the World.” As a child, he loved animals and kept many pets—including, for a time, a possum that he carried around on his head, Young recalled on a podcast in 2022. He had thoughts of becoming a veterinarian but pivoted to medicine when, in his biochemistry classes at the University of Georgia, he became fascinated with genetics and how nature manages to translate a string of letters to the behaviors necessary for survival. © 2024 Simons Foundation

Keyword: Hormones & Behavior; Sexual Behavior
Link ID: 29257 - Posted: 04.16.2024

By Carl Zimmer In the early 1900s, primatologists noticed a group of apes in central Africa with a distinctly slender build; they called them “pygmy chimpanzees.” But as the years passed, it became clear that those animals, now known as bonobos, were profoundly different from chimpanzees. Chimpanzee societies are dominated by males that kill other males, raid the territory of neighboring troops and defend their own ground with border patrols. Male chimpanzees also attack females to coerce them into mating, and sometimes even kill infants. Among bonobos, in contrast, females are dominant. Males do not go on patrols, form alliances or kill other bonobos. And bonobos usually resolve their disputes with sex — lots of it. Bonobos became famous for showing that nature didn’t always have to be red in tooth and claw. “Bonobos are an icon for peace and love, the world’s ‘hippie chimps,’” Sally Coxe, a conservationist, said in 2006. But these sweeping claims were not based on much data. Because bonobos live in remote, swampy rainforests, it has been much more difficult to observe them in the wild than chimpanzees. More recent research has shown that bonobos live a more aggressive life than their reputation would suggest. In a study based on thousands of hours of observations in the wild published on Friday, for example, researchers found that male bonobos commit acts of aggression nearly three times as often as male chimpanzees do. “There is no ‘hippie ape,’” said Maud Mouginot, a biological anthropologist at Boston University who led the analysis. As our closest living relatives, bonobos and chimpanzees can offer us clues about the roots of human behavior. We and the two species share a common ancestor that lived about 7 million years ago. About 5 million years later, bonobos split off from chimpanzees. © 2024 The New York Times Company

Keyword: Aggression; Evolution
Link ID: 29256 - Posted: 04.13.2024

By Bob Holmes Like many of the researchers who study how people find their way from place to place, David Uttal is a poor navigator. “When I was 13 years old, I got lost on a Boy Scout hike, and I was lost for two and a half days,” recalls the Northwestern University cognitive scientist. And he’s still bad at finding his way around. The world is full of people like Uttal — and their opposites, the folks who always seem to know exactly where they are and how to get where they want to go. Scientists sometimes measure navigational ability by asking someone to point toward an out-of-sight location — or, more challenging, to imagine they are someplace else and point in the direction of a third location — and it’s immediately obvious that some people are better at it than others. “People are never perfect, but they can be as accurate as single-digit degrees off, which is incredibly accurate,” says Nora Newcombe, a cognitive psychologist at Temple University who coauthored a look at how navigational ability develops in the 2022 Annual Review of Developmental Psychology. But others, when asked to indicate the target’s direction, seem to point at random. “They have literally no idea where it is.” While it’s easy to show that people differ in navigational ability, it has proved much harder for scientists to explain why. There’s new excitement brewing in the navigation research world, though. By leveraging technologies such as virtual reality and GPS tracking, scientists have been able to watch hundreds, sometimes even millions, of people trying to find their way through complex spaces, and to measure how well they do. Though there’s still much to learn, the research suggests that to some extent, navigation skills are shaped by upbringing. Nurturing navigation skills

Keyword: Learning & Memory
Link ID: 29255 - Posted: 04.13.2024

By Joanne Silberner In March, the sons of Gabriel García Márquez, the Nobel Prize-winning Colombian writer, published a posthumous novel against the specific wishes their father expressed before he died in 2014 at the age of 87. García Márquez had struggled through several versions of the book as dementia set in, and, perhaps stung by uncharacteristic negative reviews from his previous novel, didn’t want the new one published. “Until August,” the story of a woman who travels to her mother’s grave once a year and takes a new lover on each visit, got mixed reviews. Some were outright harsh. In The New York Times, Michael Greenberg wrote “It would be hard to imagine a more unsatisfying goodbye.” García Márquez’s decline, he continued, “seems to have been steep enough to prevent him from holding together the kind of imagined world that the writing of fiction demands.” Wendy Mitchell, who was an administrator with England’s National Health Service until her diagnosis of early-onset Alzheimer’s disease in 2014, recalled the moment she learned of the publication plans last year. “I type every day for fear of dementia snatching away that creative skill, which I see as my escape from dementia,” she wrote last October in The Guardian. “Maybe Márquez thought the same?” The novel’s publication raises some vital questions about living with an aging and perhaps ailing brain. What do mild cognitive impairment and dementia do to our creativity? How do these conditions affect our ability to use words, formulate sentences, and craft stories? Neuroscientists have been exploring these questions for several decades. First, a few definitions. People with mild cognitive impairment have lost more of their cognitive functioning than others their age, and often struggle to remember things. But they’re capable of managing daily activities like dressing, eating, bathing, and finding their way around. In dementia, cognitive difficulties have increased enough to interfere with daily life, and personality changes are more likely.

Keyword: Alzheimers
Link ID: 29254 - Posted: 04.13.2024

By McKenzie Prillaman It was hailed as a potentially transformative technique for measuring brain activity in animals: direct imaging of neuronal activity (DIANA), held the promise of mapping neuronal activity so fast that neurons could be tracked as they fired. But nearly two years on from the 2022 Science paper1, no one outside the original research group and their collaborators have been able to reproduce the results. Now, two teams have published a record of their replication attempts — and failures. The studies, published on 27 March in Science Advances2,3, suggest that the original results were due to experimental error or data cherry-picking, not neuronal activity after all. But the lead researcher behind the original technique stands by the results. “I’m also very curious as to why other groups fail in reproducing DIANA,” says Jang-Yeon Park, a magnetic resonance imaging (MRI) physicist at Sungkyunkwan University in Suwon, South Korea. Science said in an e-mail to Nature that, although it’s important to report the negative results, the Science Advances studies “do not allow a definitive conclusion” to be drawn about the original work, “because there were methodological differences between the papers”. In conventional functional MRI (fMRI), researchers monitor changes in blood flow to different brain regions to estimate activity. But this response lags by at least one second behind the activity of neurons, which send messages in milliseconds. Park and his co-authors said that DIANA could measure neuronal activity directly, which is an “extraordinary claim”, says Ben Inglis, a physicist at the University of California, Berkeley. © 2024 Springer Nature Limited

Keyword: Brain imaging
Link ID: 29253 - Posted: 04.11.2024

By Joanne Silberner A hug, a handshake, a therapeutic massage. A newborn lying on a mother’s bare chest. Physical touch can buoy well-being and lessen pain, depression and anxiety, according to a large new analysis of published research released on Monday in the journal Nature Human Behaviour. Researchers from Germany and the Netherlands systematically reviewed years of research on touch, strokes, hugs and rubs. They also combined data from 137 studies, which included nearly 13,000 adults, children and infants. Each study compared individuals who had been physically touched in some way over the course of an experiment — or had touched an object like a fuzzy stuffed toy — to similar individuals who had not. For example, one study showed that daily 20-minute gentle massages for six weeks in older people with dementia decreased aggressiveness and reduced the levels of a stress marker in the blood. Another found that massages boosted the mood of breast cancer patients. One study even showed that healthy young adults who caressed a robotic baby seal were happier, and felt less pain from a mild heat stimulus, than those who read an article about an astronomer. Positive effects were particularly noticeable in premature babies, who “massively improve” with skin-to-skin contact, said Frédéric Michon, a researcher at the Netherlands Institute for Neuroscience and one of the study’s authors. “There have been a lot of claims that touch is good, touch is healthy, touch is something that we all need,” said Rebecca Boehme, a neuroscientist at Linkoping University in Sweden, who reviewed the study for the journal. “But actually, nobody had looked at it from this broad, bird’s eye perspective.” © 2024 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 29252 - Posted: 04.11.2024

By Nicole Rust We readily (and reasonably) accept that the causes of memory dysfunction, including Alzheimer’s disease, reside in the brain. The same is true for many problems with seeing, hearing and motor control. We acknowledge that understanding how the brain supports these functions is important for developing treatments for their corresponding dysfunctions, including blindness, deafness and Parkinson’s disease. Applying the analogous assertion to mood—that understanding how the brain supports mood is crucial for developing more effective treatments for mood disorders, such as depression—is more controversial. For brain researchers unfamiliar with the controversy, it can be befuddling. You might hear, “Mental disorders are psychological, not biological,” and wonder, what does that mean, exactly? Experts have diverse opinions on the matter, with paper titles ranging from “Brain disorders? Not really,” to “Brain disorders? Precisely.” Even though a remarkable 21 percent of adults in the United States will experience a mood disorder at some point in their lives, we do not fully understand what causes them, and existing treatments do not work for everyone. How can we best move toward an impactful understanding of mood and mood disorders, with the longer-term goal of helping these people? What, if anything, makes mood fundamentally different from, say, memory? The answer turns out to be complex and nuanced—here, I hope to unpack it. I also ask brain and mind researchers with diverse perspectives to chime in. Among contemporary brain and mind researchers, I have yet to find any whose position is driven by the notion that some force in the universe beyond the brain, like a nonmaterial soul, gives rise to mood. Rather, the researchers generally agree that our brains mediate all mental function. If everyone agrees that both memory and mood disorders follow from things that happen in the brain, why would the former but not the latter qualify as “brain disorders”? © 2024 Simons Foundation

Keyword: Depression; Learning & Memory
Link ID: 29251 - Posted: 04.11.2024

Jon Hamilton A sibling can change your life — even before you're born. That's because when males and females share a womb, sex hormones from one fetus can cause lasting changes in the others. It's called the intrauterine position phenomenon, or intrauterine position effects, and different versions of it have been observed in rodents, pigs, sheep — and, probably, humans. "It's really kind of strange to think something so random as who you develop next to in utero can absolutely change the trajectory of your development," says Bryce Ryan, a professor of biology at the University of Redlands. The phenomenon is more than a scientific oddity. It helped establish that even tiny amounts of hormone-like chemicals, like those found in some plastics, could affect a fetus. Cattle breeders in ancient Rome may have been the first people to recognize the importance of a sibling's sex. They realized that when a cow gives birth to male-female twins, the female is usually sterile. These females, known as freemartins, also act more like males when they grow up. Scientists began to understand why in the early 1900s. They found evidence that hormones from the male twin were affecting the female's development. The effect is less obvious in other mammals, Ryan says. Female offspring in rodents, for example, can still reproduce, but they have measurable differences in sexual development and tend to be more aggressive. © 2024 npr

Keyword: Sexual Behavior; Hormones & Behavior
Link ID: 29250 - Posted: 04.11.2024